Yeast VSM1 Encodes a v-SNARE Binding Protein That May Act as a Negative Regulator of Constitutive Exocytosis

Volume 19, no. 6, p. 4480-4494, 1999. In this article, a novel SNARE-interacting protein in yeast, Vsm1/Ddi1, was characterized. During more recent studies of this protein, we discovered that the original cloned Saccharomyces cerevisiae open reading frame (YER143w) used for our work, which was generated by PCR amplification, contained two point mutations (G substitutions at bp 925 and 1282 relative to the sequence deposited in the Saccharomyces Genome Database) that resulted in two amino acid substitutions (R309G and Q428E, respectively). Therefore, for our subsequent work with this protein, we have corrected these mutations. Regrettably, restoration of these two altered residues changes some of the results that we previously reported. We originally reported that overproduction of the mutant version exacerbated the growth defect of sec9-4 mutant cells (Fig. 3), whereas we now find that overproduction of the corrected version partially suppresses the temperature-sensitive phenotype of sec9-4 yeast cells. As best as our current analysis has determined, it appears that the results shown in Fig. 1, 2, and 5 to 8 remain valid, although we cannot exclude the possibility that the accumulation of secretory vesicles, shown in Fig. 4, results from the mutations. A fuller description and documentation of these new findings appear in Mol. Biol. Cell 19:3625-3637, 2008.